#!bin/bash

# 数学计算.

NUMBER=7
let RESULT=NUMBER+5

echo Result: $RESULT

let RESULT2=$[NUMBER + 5]

echo Result2: $RESULT2

let RESULT3=`expr 2 + 3`

echo Result3: $RESULT3

RESULT4=`echo "$NUMBER * 1.9" | bc`
echo $RESULT4

